The diagnosis of cluster headache is typically made after the history of headaches has been explored and a physical examination is completed. Cluster headaches are unique in their presentation, and often the history is sufficient to make the diagnosis. While no imaging study or specific blood test can confirm the diagnosis of cluster headache, an MRI or CT scan of the brain may be ordered to confirm that there are no other contributing factors that may mimic cluster headache symptoms. In some cases, ophthalmologic evaluation is needed to exclude problems within the eye itself that may be causing symptoms.